New research is shedding light on how weight-loss and diabetes medications like Ozempic, Wegovy, and Mounjaro affect not only appetite but also the brain.
These medications belong to a group of drugs known as GLP-1 receptor agonists.
Originally developed to help people with type 2 diabetes, they’ve now become popular treatments for obesity because they reduce hunger and lead to weight loss.
These drugs mimic a hormone naturally released in the gut after eating. This hormone signals the brain that you’re full and helps control blood sugar.
But although they’re effective, up to 40% of people who take these drugs suffer from nausea, vomiting, or other side effects that make it hard to continue treatment.
At the upcoming Neuroscience 2025 meeting — the world’s largest brain research conference — scientists will present new findings that show how these medications affect specific brain regions tied to nausea, reward-driven behaviors (like overeating), and even thirst.
They’re also exploring how to improve these drugs by keeping the benefits and removing the downsides.
One study in obese rats found that when researchers combined small doses of tirzepatide (Mounjaro) with the hormone oxytocin, the rats lost more weight than with either treatment alone — and without the usual signs of nausea. That’s a big step, because oxytocin seems to boost the drug’s benefits without adding discomfort.
Another study looked at two key areas in the brain: the “vomit center” (area postrema) and a nearby area that controls fullness.
It turns out the vomit center is responsible not just for nausea, but also for the weight-loss effects of GLP-1 drugs. This means it might be possible in the future to target other brain areas for weight loss — and avoid nausea altogether.
There’s also evidence that these drugs change how the brain processes rewards. One team found that a specific part of the amygdala (a brain area tied to emotions) helps reduce the craving for highly pleasurable food.
When this brain region is activated by GLP-1 drugs, it sends signals that turn down the brain’s reward circuits — including dopamine responses — so people may feel less driven to overeat or binge.
Interestingly, the same types of medications also reduce thirst, and researchers found changes in brain areas related to hydration. This suggests that these drugs don’t just influence hunger, but also a broader set of motivated behaviors that involve the brain’s internal balance systems.
Dr. Lorenzo Leggio from the U.S. National Institute on Drug Abuse says these findings show that GLP-1 drugs could help with more than just diabetes and weight loss. They might also help treat binge eating or even addiction, since those conditions involve similar reward pathways in the brain.
These studies offer new hope for developing better medications that work with the brain’s natural systems — making treatments more effective, less uncomfortable, and possibly helpful in more conditions than previously imagined.
If you care about weight loss, please read studies that hop extract could reduce belly fat in overweight people, and early time-restricted eating could help lose weight .
For more health information, please see recent studies about a simple path to weight loss, and results showing a non-invasive treatment for obesity and diabetes.
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